Controller (computing): Difference between revisions

Revision as of 08:24, 5 November 2012

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==Mainframe controllers==

[[File:BRL64-IBM 1311 DiskDrives.jpg|thumb|iight|text-top|220px|IBM 1311 Disk Drives -. Model 23 (Slaveon right) &contains Modelan integrated controller for itself and up to 3 Model 2s (Masteron left).<ref>{{cite book|last=IBM TheCorporation|title=IBM ModelSystems 3Reference containsLibrary anIBM integrated1311 controllerDisk Storage Drive|url=http://bitsavers.]]informatik.uni-stuttgart.de/pdf/ibm/140x/A26-5991-0_1311diskDrive.pdf}}</ref>{{rp|p.2}}

]]In IBM terminology a ''controller'' is "a device that decodes the [channel] command and effects the operation of the device."<ref>{{cite book|last=IBM Corporation|title=Introduction to IBM Data Processing Systems|year=1978|url=http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/generalInfo/GC20-1684-4_IBMdpIntroJul78.pdf}}</ref>{{rp|p.5-1}}

In most mainframe systems a device-independent [[Channel I/O|''channel'']] usually attaches to the CPU and a controller or control unit implements device-dependent logic for attaching specific devices to the channel. Some devices have integrated control units.